👉 In mathematics, a quadrantal angle is an angle whose terminal side lies on a fixed point in the plane. These angles are defined as follows: 1. The first quadrant of a coordinate system consists of all angles that lie in one of the four quadrants (positive x-axis, negative y-axis, positive z-axis, or negative x-axis) and are located to the right of the origin. 2. Quadrantal angles can be categorized into two types: standard angles (such as 0°
